1. Field of the Invention
This invention relates to water treatment systems and in particular to a portable water clarifier which can be transported to a source of sediment-contaminated water and which is capable of treating the contaminated water to remove sediment therefrom and return clarified water to the source.
The portable water clarifier of the present invention has particular use in removing sediment collected in the basin of industrial cooling towers. Cooling towers are commonly located in industrial process plants and refineries throughout the country and range in size from one cell cooling towers to those which contain a plurality of attached cells. Cooling towers provide a source of cool water for use in removing process heat from the plants or refineries. Cooling towers are designed to draw air into the cooling tower, contacting and cooling the heated water running into the basin of the tower. Dirt and dust carried with the ambient air into the cooling tower settles in the basin contaminating the cooling water. This sediment must be removed periodically so that the cooling water will efficiently remove process heat. Previous methods of cleaning cooling tower basins do not return water which has been removed from the cooling tower during removal of the sediment and clarified to the cooling tower. Typically such methods include pumping the sediment from the basin of the cooling tower directly into a nearby trench; pulling sediment and water by vacuum directly into a vacuum truck; draining the cooling tower and removing the sediment that remains by vacuum truck or other removing means. Such operations do not operate continuously to return water to the cooling tower while removing sediment and thereby result in excessive losses of water or involve shutting the cooling tower down, resulting in loss of production time.
2. Disclosure Statement
Water treatment systems have been proposed in the past utilizing a plurality of treatment steps to remove the contaminants. These prior art systems generally have been cumbersome and time-consuming and are not capable of removing large quantities of sediment from industrial size basins and yet be portable. Several patents which disclose waste water treatment facilities which comprise a plurality of treatment stages include U.S. Pat. No. 4,008,159, issued Feb. 15, 1977, and U.S. Pat. No. 1,160,918, issued Nov. 16, 1915. These two patents, while disclosing multi-stage treatment, do not disclose the specific structure by which the present invention removes sediment and produces a clarified water product which is returned to its source. U.S. Pat. No. 3,992,300, issued Nov. 16, 1976, discloses a multi-stage apparatus for controlling iron content of a zinc phosphating bath. U.S. Pat. No. 2,620,926, issued Dec. 9, 1952, discloses a multi-stage apparatus for treating liquids with activated carbon. U.S. Pat. Nos. 2,753,877, issued July 10, 1956 and 2,365,293, issued Dec. 19, 1944, disclose single-stage water treating apparatus in which the contaminated water is passed over baffles and the like in a tortuous path in order to separate the solid matter from the water. U.S. Pat. No. 3,920,552, issued Nov. 18, 1975, discloses a portable water treatment system comprising a mixing tank having means for drawing ambient water from a nearby lake, stream or river for selectively introducing air or chemicals into the water and for thoroughly mixing the water and any air or chemicals so introduced to treat the water. The treated water is then returned to its source. The mixing tank of this patent is a single-stage and is unlike the multi-stage water clarifier of the present invention.